66741

Appears in sequences

• Conjectured smallest Sierpiński numbers of the second kind S, base b=2,3,4,5,..., where S*b^n+1 is composite for all n>=1 and gcd(S+1, b-1) = 1.at n=2A123159
• Numbers k such that sum of the divisors of k equals the sum of the reversals of the divisors of k. Numbers with all palindrome divisors are not in the sequence.at n=30A196677
• Odd numbers n divisible by 3 such that for all k >= 1 the numbers n*2^k + 1 and n*2^(k+1) + 1 do not form a pair of primes.at n=6A243857
• Odd numbers n not congruent to 5 mod 6 such that for all k >= 1 the numbers n*4^k + 1 are composite.at n=0A251057
• Odd numbers n divisible by 3 such that for all k >= 1 the numbers n*4^k + 1 are composite.at n=0A256002